[PATCH 6.4 490/800] riscv: uprobes: Restore thread.bad_cause

Greg Kroah-Hartman
2023-07-16T20:17:54Z

From: Tiezhu Yang <yangtiezhu@loongson.cn>

[ Upstream commit 58b1294dd1d65bb62f08dddbf418f954210c2057 ]

thread.bad_cause is saved in arch_uprobe_pre_xol(), it should be restored
in arch_uprobe_{post,abort}_xol() accordingly, otherwise the save operation
is meaningless, this change is similar with x86 and powerpc.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Guo Ren <guoren@kernel.org>
Fixes: 74784081aac8 ("riscv: Add uprobes supported")
Link: https://lore.kernel.org/r/1682214146-3756-1-git-send-email-yangtiezhu@loongson.cn
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/riscv/kernel/probes/uprobes.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/riscv/kernel/probes/uprobes.c b/arch/riscv/kernel/probes/uprobes.c
index c976a21cd4bd5..194f166b2cc40 100644
--- a/arch/riscv/kernel/probes/uprobes.c
+++ b/arch/riscv/kernel/probes/uprobes.c
@@ -67,6 +67,7 @@ int arch_uprobe_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
struct uprobe_task *utask = current->utask;

WARN_ON_ONCE(current->thread.bad_cause != UPROBE_TRAP_NR);
+ current->thread.bad_cause = utask->autask.saved_cause;

instruction_pointer_set(regs, utask->vaddr + auprobe->insn_size);

@@ -102,6 +103,7 @@ void arch_uprobe_abort_xol(struct arch_uprobe *auprobe, struct pt_regs *regs)
{
struct uprobe_task *utask = current->utask;

+ current->thread.bad_cause = utask->autask.saved_cause;
/*
* Task has received a fatal signal, so reset back to probbed
* address.
--
2.39.2